Manufacture of sheet-glass.



No. 805,064. PATBNTEI) NOV. 21, 1905.

H. K. HITCHCOCK.

MANUPACTURE 0F SHEET GLASS.

APPLIOATION FILED AUG. 14, 1901.

4 SHEETS-SHEET 1.

WITNESSES:

PATENTED NOV. 2l, 1905.

H. K. HITCHCOCK. MANUFACTURE 0F SHEET GLASS.

APPLICATION FILED AUG. 14, 1901.

4 SHEETS-SHEET Z.

INVENTOR Whit/*MW Atr'y.

TNESSES: i fr?.

No. 805,064. TATHNTHD HCV. 21, 1905. H. K. HITCHCOCK.

MANUTACTHHH CT sHHHT CLASS.

APPLICATION FILED AUG. 14, 1901.

l l4 SHEETS-SHEET 3.

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No. 805,064. PATENTBD NOV.k 2l, 1905. H. K. HITCHCOCK.

MAUPAGTURE OP SHEET GLASS.

APPLICATION FILED AUG.14, 1901.

4 SHEETS-SHEET 4.

iNVENTOR pNirnp STATES PATENT OFFICE.

HALBERT K. HITCHCOCK, OF AKRON, OHIO, ASSIGNOR TO HIMSELF AND CHARLESIN. BROWN, TRUSTEES, OF PITTSBURG, PENNSYLVANIA.

IVIANUFACTURE OF SHEET-GLASS.

To ct wlwnt it may concern:

Be it known that I, HALBERT K. HITCHCOCK, a citizen of the UnitedStates, residing at Akron, in the county of Summit and State of Ohio,have invented or discovered certain new and useful Improvements in theManufacture of Sheet-Glass, of which improvements the following is aspecification.

The invention described herein relates to certain improvements in themethod of manufacturing sheets or plates of glass direct-i. c. withoutforming the glass into cylinders.

It has heretofore been attempted to form sheets by drawing the glass insheet form from a furnace or other suitable receptacle. This method hasbeen unsuccessful, for the reason that the pull effected a narrowing orred uction of transverse area in all directions, so that the sheet israpidly reduced in width, fining down to `a mere strand. It has alsobeen attempted to form sheets by forcing the glass through a long narrowslot, but unsuccessfully, as the pressure of the glass as it emergesfrom the slot effected an upsetting or thickening of the glass inadvance.

The object of the present invention is to provide for such a forced feedof the glass at the point where a shaping pull is exerted as tocompensate for any reduction in width resulting from the shaping ordimensioning pull or draft. The invention is hereinafter more fullydescribed and claimed.

In the accompanying drawings, forming a part of this specification,Figure l is a sectional elevation of a form of apparatus suitable forthe practice of my invention. Fig. 2 is a vertical section on a planeindicated by the line II II, Fig. l. Fig. 3 is an enlarged detail viewof the lower portion of the pulling mechanism. Fig. 4 is a sectionalplan view, the plane of section being indicated by the line IV IV, Fig.l. Fig.5 is a View similar to Fig. 1, illustrating a modified form ofapparatus for the practice of the invention. Fig. 6 is an enlargedsectional elevation of the controlling-rollers and severing mechanism;and Fig. 7 is a view, partly in front elevation and partly in section,of the parts shown in Fig. 6.

In the practice of my invention the glass in a molten condition iscaused to flow or eXude from a suitable containing vessel or chamber 1and preferably exude from a chamber or passage-way which has preferablya trans- Specication of Letters Patent.

Application lled August 14, 1901. Serial Nol 71,980.

Patented Nov. 2l, 1905.

verse length at the point of formation of the glass equal orapproximately equal to the width of sheet to be produced. In order torender it certain that the glass shall be of the proper temperature asit exudes from the channel, it is preferred to provide suitable meanswhereby the glass maybe heated or cooled as it flows along the channelor passageway. A convenient means to this end 'consists in embedding anumber of rods 3 of suitable conducting material, as carbon, in thewalls of the passage and connecting them in sets of two or more to asuitable electric generator, so that the temperature at any portion ofthe channel or passage-way may be increased or diminished by regulatingthe current. In case the glass is too hot as it Hows from the receptacleit' can .be conveniently cooled by forcing a stream of air or othercooling Huid against a thin portion 4 of the wall of the passage. Thisthin portion is formed by recessing the wall of the passage, as shown.Except when a cooling down is required this recess should be filled witha piece of non.-

conducting material, as brick or tile 4, to i prevent loss of heat byradiation. As the glass exudes from the feed or shaping channel or slotit is .subjected to a stretching or elongation, whereby it is brought tothe desired thickness. If only the pull on the glass affected theeXudation of the glass through the slot, the sheet produced wouldrapidly diminish in width; but by so regulating the forced feed and thepull on the sheet that they are equal the glass fed will alwayscompensate for the tendency to reduction in transverse area due to thepull.

While any suitable mechanism known in the art may be employed foreffecting the elongation and consequent transverse reduction of theglass, it is preferred to employ the mechanism shown. This mechanismconsists of a'pair of endless chains 5, passing over sprocket-wheels 6and 7 the former being secured to a driven shaft 8, mounted in suitablebearings on the frame 9 and driven, through suitable interposed gearing,vby a motor 10. The wheels 7 are carried by a shaft 11, supported inbearings on the frame 9 and so arranged with reference to the feedslotthat the upward-moving portions of the chains will be in a planeparallel with a vertical plane passing through the slot` as shown inFig. 1. The chains are provided with a IOO IOS

series of hooks 12 for engagement with the glass clamp or grip. It ispreferred that the hooks should be yieldingly connected to the chains toprevent any sudden shock or strain to the glass when the grips arecaused to engage the sheet. A convenient construction for this purposeconsists of rods 13, secured to cross-pins 14 of the chains and servingas guides for the hooks, which are provided with eyes 15 for thereception of the rods. rlhe hooks are supported by springs 16,surrounding rods, as shown in Fig. 3. The grip consists of a bar 17,provided with grippingfingers 18 so constructed and mounted that by apartial rotation they will clamp the edges of the glass against the bar.The bar is provided outside of the fingers with wheels 19, looselymounted thereon and adapted to move along suitable rails in theannealingoven, as hereinafter described.' A series of these grips isplaced on inclined supportingrails 20, which extend down to suitableproximity to the lower sprocket-wheels 7 or to the path of the hooks 12as they are carried around the sprocket-wheels 7. Suitable stopmechanism is employed to insure the presentation of the grips one at atime to the hooks. This stop mechanism consists of leversv 21, pivotallymounted on the yrails outside of the paths of movement of the grips, butprovided with lugs 22 and 23, projecting into the path of movements ofthe grips. These lugs are so arranged on the levers 21 that when thelatter are supported in normal position by the springs 24, which bear atone end against the lever and at the opposite end against abutments 25on the rods 26, secured to the rails 20, the lugs 23 will be slightlyabove the path of movement of the ends of the grips, while the lugs'22will lie in such path of movement.

4The lugs are arranged a distance apart approximately equal to thedistance between the ends of adjacent grips as they lie upon thesupporting-rails 20. In order to allow one of the grips to drop down toposition where it will be caught by one of the hooks 12, cams 27 (shownby dotted lines in Fig. 3) are secured upon the shaft 11 in suchposition that just before the hooks reach the points where they willengage one of the grips the cams will strike upon the levers 21A anddepress them sufficiently to shift the stops 23 in front of one of thegrips and the stops 22 from in front of the lowest grip, therebypermitting the lowest grip to drop down to proper position to be caughtby the hooks. As the cams pass out of contact with the levers the latterare raised by the springs, so as to permit the grip retained by thestops 23 to drop down against the stops 22, where it will be held untilanother hook comes into proper position. As the grips are carried aroundby the hooks portions of the fingers 18 will lie outside of the edgesof' the sheet of glass being drawn until such portions reach theclosingkthe other blade.

stops 28, which are secured to the frame 9, as clearly shown in Fig. 3.By the engagement of these fingers with the closing-stops the fingersare turned down in front of the sheet, pressing the edges thereofagainst shoulders formed on the gripping-bar 17.

By the operation of the chains and gripping-bar the sheets are drawn toa suitable height, and provision is made for severing the sheetimmediately above each bar after the preceding griphas reached apredetermined height dependent upon the length of sheet desired. A-convenient mechanism for that purpose is clearly shown in Figs. 1, 2,and 4 and consists of blades 29, provided at their ends with trunnions30, which are mounted in suitable bearings on the frame 9. These bladesare arranged on opposite sides of the plane of movement of the sheet andare rotated so that their inner or cutting edges while operating tovcrack the sheet are moved in the same direction and at the same speedas the sheet. This rotation of the blades is effected by means ofrack-.bars 31, secured to the lifting-chains 5 in such relation to thehooks 12 that the blades will be brought around so that their inneredges will simultaneously contact with and bear upon opposite sides ofthe sheet in a line a short distance above the grip. This rack-barintermeshes with a pinion 32, secured upon the trunnion of one of theblades and intermeshing with a corresponding pinion 33 of the trunnionof It is preferable that the hooks and severing mechanism should be solocated with relation to the travel of the sheets that the blades willoperate upon the sheet just at the time that the preceding grip isbeginning to pass around the upper sprocket-wheels 6, so that a slightbend or exure will be given to the sheet, thereby facilitating itscracking olf at the point or line of pressure of the blades.

The grips are carried around the sprocketwheel 6, with the severedsection suspended therefrom, and the rollers 19 on the grips aredeposited upon the inclined rails 34, which extend into a suitableannealing-oven. The travel of the grips with the sheets through theannealing-oven is controlled by endless chains 35 passing aroundsprocket-wheels 36, one of'which is driven through suitable interposedgearing by the motor 10. The chains are provided with projections 37,which extend down suiiiciently to engage the grips and regulate theirmovement down the inclined rails.

The sides of the front end of the annealingchamber are formed by plates38, which eX- tend between the chains 5 and are slotted for the movementof the projecting ends of the several grips. These side plates extenddown to or a little beyond the severing mechanism, and the front of theannealing-chamber is closed by a movable door 39, which also ex- IIO IIS

tends down to a suitable support 40 in proximity to the severingmechanism. This construction will entirely protect the sheets as theyare drawn up between the severing mechanism from drafts of air, whichwould be liable to eect an unequal cooling and consequent warping of thesheets.

1n forming sheets with the apparatus described the glass in the furnaceis maintained at such a level above the orice of the channel or slot asto produce suflcient pressure to leffect the desired flow or movement ofthe sheet to permit the grips to engage there.

with. Thereafter the grips are caused to engage the edges of the sheetautomatically and at suitable intervals in the manner described. Whilenot necessary, it is preferred to arrange cooling-rollers41 adjacent thepoint at which formation of the sheet begins and on opposite sides ofthe line of movement of the sheet. These rollers should bear against thesides of the sheet, so as to have a cooling and calendering effectthereon. It is preferred to support the rollers in such manner thattheir pressure would be due to and controlled entirely by the weight ofthe rollers themselves. To this end arms 42 are adjustably secured tosuitable supports at opposite ends of the passage-way or channel in suchmanner as to serve as supports for the journals of the rollers 41. Bychanging the angle of these supporting-arms the rollers c an be causedto bear with greater or less pressure against the sides of the sheet. Ifnecessary, blast-pipes 43, having their discharge-openings arranged ltocause the air to impinge upon the glass, can be arranged in suchrelation to the slot as to cool the glass as it flows therefrom.

As shown in Figs. 5, 6, and 7, gravity may be employed for effecting thestretching and consequent thinning of the sheets or shaping of otherarticles. AS shown in Fig. 5, the channel or passage-way is so formedthat the flow of glass through the channel is effected by or is due tothe controlled action of gravity. As the sheet elongates it passesdownbetween a series of pairs of rollers 44, mounted in suitable bearings onopposite Sides of the path of movement of the-sheet. These rollers bearlightly upon the surfaces of the sheet and are rotated in such manner asto control the downward movement of the sheet and regulate the pull onthe glass as it iiows from channel or passage-way, therebycounterbalancing the increasing weight of the sheet as it is formed andmaintaining a uniform pull on the glass as it is forcedthrough thechannel. In order to regulate the pressure of these rollers on thesheet, their bearings are formed at the ends of the arms 45, pivotallymounted upon the side frames 46. Rods 47 are passed through slots in oneof each of the pairs of the arms and are connected to the opposite armof the pairs. Said arms are drawn toward each other to increase thepressure of the rollers of the sheets by means of hand-wheels 48,screwing onto the ends of the rods and bearing, through the medium ofsprings 49, against one of the arms. The pivots are so arranged thatwhen hanging freely the rollers 'will barely contact with the sides orsurfaces of the sheet. On the journals, at one end of these rollers` aresecured worm-wheels 50, which intermesh with worms on the shaft 5l. Thisshaft is driven by a suitably-arranged motor. The severing mechanism,which is arranged below the regulating-rollers, is similar to thatdescribed in connection With the construction shown in Fig. 1 andconsists of blades 29, rotatively mounted and driven at the same rate ofspeed as the feed of the glass by a worm 52 on the shaft engagingworm-wheels 53 on the trunnions of the blades. One of the blades isadjustably mounted, so that it can be moved toward and from the other,according to the thickness of glass operated. This adjustment, however,will not be sufiicient to shift worm-wheel 53 out of engagement with theWorm 52.

A desirable mechanism for receiving the sheet as it is severed by theblades consists of a series of fingers 54, carried by sprocketchains 55,which pass through the annealingoven. These fingers are supported orbraced in receiving position by arms 55, extending down to thesprocket-chain. On the fingers are mounted blocks 56, yieldinglysupported by springs 57, surrounding the fingers. The

sprocket-chains 55 are' so moved with relation to the rate of formationof the sheet that the blocks 56 will be brought immediately under thelower end of the sheet just at the time that the blades operate on thesheet, so that by the continued forward movement of the fingers a slightflexure of the sheet is effected to facilitate or complete the crackingoff of the sheet.

After being cracked the sheet will rest in an inclined position upon thelingers and will be carried through the annealingoven. The front end ofthe annealing-oven is closed by a metal shell 5 8, having a slot for theentrance of the sheet to prevent any unequal cooling of the sheets.

1t is characteristic of thel method heretofore attemptedz'. e. pullingthe sheet from a body of molten glass-that the narrowing occurs closelyadjacent to the molten body or point of greatest plasticity of thesheet; but by feed- IOO IIO

ing the glass to the point where the pull or elongation occurs, so thatthere will be a constant and uniform supply, and by cooling the glass asthe elongation occurs all narrowing of the sheet is avoided. It ispreferred that sufficient quantity of glass should be forced out to forma body outside of the slot somewhat wider and thicker than thecorresponding dimensions of the sheet to be formed, so that the glasswill have opportunity to lose somewhat of its plasticity through thecooling action of the air-jets. The rollers 41 are located so as tocontact with the sheet just as it reaches the desired thickness,and asthe rollers are cooled by the circulation of fluid therethrough thesheet will be hardened to such an extent that no further change in itsdimensions will be effected. Y

When using the apparatus shown in Fig. the glass is forced out of theslot in a sheet having nearly the thickness and width required, andprovision is made for chilling the glass as it exudes from the slot byjets of air from the blast-nozzles 59. It will be understood that inbeginning the operation a perfect sheet will not be formed untilsuflicient weight of glass has flowed out to exert the required pull onthe glass as it comes from the slot. As soon as sufficient weight ofglass has passed out the rollers 44E are adjusted against the sheet, soas to maintain a uniform tension on the glass as it exudes from theslot. These rollers may be made to bear only lightly on the glass and berotated in the direction opposite the movement of the glass or they maybe caused to grip the sheet and be rotated in the direction of themovement of the sheet.

It is characteristic of my improvement that the glass as forced from theslot is subjected to a regulated tension, so as to carry the glass awayas or nearly as it is forced through the slot. In one case the tensionis produced by mechanism operating to overcome the force of gravity andin the other case gravity controlled or regulated affects the tension orpull 4 Vthe glass. y

I claim herein as my inventionl. In an apparatus for forming sheets ofglass, the combination of a receptacle for the glass havingadischargeslot or opening,means for forcing the glass through said slot oropening, means Alor applying a regulated tension to the glass wherebythe glass is pulled away from the slot at or approximately at the rateof feed through the slot and means for severing the glass beyond theline or point at which tension is applied, substantially as set forth.

2. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass havingadischarge slotor opening, means forforcing the glass through said slot or ope'ning, means for regulatingthe temperature of the glass as it Hows through the slot or opening,means for applying a regulated tension to the glass, whereby the glassis pulled away from the slot at or approximately at the rate of feed andmeans for severing the glass beyond the line or point at which tensionis applied vthrough the slot, substantially as set forth.

3. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass having a discharge slot'or opening, means forforcing the glass through said slot or opening, a mechanism arrangedin aplane parallel or approximately parallel with the direction of feed ofthe glass through the slot adapted to pull the glass away from the slotyat or approximately at the rate of feed of glass through the slot andmeans for severing the glass beyond the line or point at which tensionis applied, substantially as set forth.

4. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass having a discharge slot or opening, means forforcing the glass through said slot or opening, a pulling mechanismarranged in the plane of feed of the glass through said slot or opening,and a series of grippers for connecting the glass sheet or plate to thepulling mechanism, substantially as set forth.

5. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass having a discharge slot or opening, means forforcing the glass th rough said slot or opening, means for applying aregulated tension to the glass whereby it is pulled away from the slotat or approximately at the rate of feed through the slot and meansoperated by the tension mechanism for cracking the glass atpredetermined points or intervals, substantially as set forth.

6. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass havingadischarge slot or opening, means forforcing the glass through said slot or opening, a pulling mechanismarranged in a plane parallel to the vdirection of feed of glass throughthe slot, rotatable blades operated by the pulling mechanism forcracking the glass larranged to operate at predetermined intervals,substantially as set forth.

7. In an apparatus for forming sheets of glass, the combination ofareceptacle for the glass having adischarge slot or opening, means forforcing the glass through said slot or opening, a pulling' mechanismarranged in the plane of feed of glass through the slot, a series ofgrippers detachably connected to the pulling mechanism and mechanism forfeeding the grippers to the pulling mechanism one at a time,substantially as set forth.

8. The combination of a glass-containing chamber or receptacle, anorifice having a shape substantially similar to that of the article tobe formed, located outside of the chamber but connected thereto, meansfor causing a iow of glass from the chamber to a formative point in saidorifice, means for applying continuously a stretching tension to theglass in such manner as to remove the glass from the orifice at a rateequal to the movement of the glass thereto and means for cooling theglass from the formative point outwardly or in the direction of pull,substantially as set forth.

9. The combination of means for bringing a mass of glass to a shapesimilar to that of the desired product, means for cooling the glass atthe point at which it assumes the desired shape and means for applyingtension to such initial shape for reducingthe shape to the desireddimensions without material alteration of the shape in transversesection, at a rate equal or approximately equal to the rate of initialformation.-

10. The combination of a glass-containing chamber or receptacle, anorifice having a shape similar to that of the article desired connectedto the chamber, means for causing a fiow of glass to the orifice, aheated chamber and means adapted to pull the glass from the orifice at a-rate equal or approximately equal to the iiow of glass to the orificeand deliver the sheet while hot into the heated chamber, substantiallyas set forth.

11. The combination of a glass-containing chamber or receptacle, anorifice having a shape similar to that of the article desired connectedto the chamber, means for causing a flow of glass to the orifice, aheated chamber above the orifice and means adapted to pull the glassfrom theI orifice and deliver it into the heated chamber', substantiallyas set forth.

12. The combination of a glass-containing chamber or receptacle, anorifice or opening `having a shape similar to that of the articledesired, means for causing a flow of glass to the orifice or opening, aheated chamber, means for pulling' the glass from the orifice oropening' and delivering it into the heated chamber and means forsevering the glass into lengths or sections, substantially as setforth.

13. The combination of a glass-containing chamber or receptacle, anorifice or opening having a shape similar to that of the articledesired, means for causing a flow of glass to the orifice or opening,ahcated chamber above the orifice, means for pulling the glass from theorifice or opening and delivering it into the heated chamber and meansfor severing the glassintolengths or sections, substantially as setforth.

14. The combination of a glass-containing chamber or receptacle, a slotor orifice connected to the chamber, means for positively forcing moltenglass up through such slot or orifice, means for cooling the surface ofsuch glass to the line o f contact with such slot or orifice, meansoperative to stretch such glass as it emerges from such slot or orifice,substantially as set forth.

15. The combination of a glass-containing chamber, a slot or orificeconnected to the chamber, means for positively forcing molten glassthrough such slot or orifice, means for cooling the surface of the glassas it passes out of such slot or orifice to the line of contact on suchslot or orifice, a heated chamber, means operative to stretch such glassas it emerges from such slot or orifice and deposit it -in a heatedchamber, substantially as set forth.

16. The combination of a receptacle for molten glass having adischarge-orifice connected therewith, means for forcing the glass tosuch orifice, means for regulating the temperature of the glass as itpasses to such orifice, means for cooling said glass as it leaves saidorifice and a pulling apparatus for taking the glass away as fast as itis fed to such apparatus, substantially as set forth.

17. In an apparatus for the formation of sheets of glass the combinationof a receptacle for holding molten glass, a discharge. slot or openingconnected therewith of a shape similarv to the finished article, meansfor forcing the molten glass to a formative point at or near the end ofsaid slot or opening, a heated chamber, means for applying a regulatedtension upon the glass and moving it into the chamber whereby the glassis pulled away at or approximately at the same speed as the movement ofthe glass to such formative point, substantially as set forth.

18. rlhe combination ofareceptacle for molten glass having a dischargeslot or opening connected therewith, means for forcing the glass to aformative point at or near the end of said opening, means for regulatingthe temperature of the glass in its passage to such formative point,means for applying a regulated tension to the glass whereby it is pulledaway at a rate equal or approximately equal to the rate of feed to suchformative point and a means for cooling the surface of said glass undertension to the line of contact with the retaining-walls at suchformative point, substantially as set forth.

19. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass, an upwardly-discharging slot or openingoutside of the receptacle but connected therewith, means for forcing theglass through said slot or opening, means for applying a regulatedtension to the glass whereby the glass is pulled away from the slot ator appr'oXimately at the rate of feed through thel slot and means forsevering the glass beyond the line or point at which tension is applied,substantially as set forth.

20. In an apparatus for forming sheets of glass, the combination of areceptacle for the glass, an upwardly-discharging slot or openingoutside of the receptacle but connected therewith, means for forcing`the glass th rough said slot or opening, means for regulating thetension on the glass as it flows through the IOO ISO

direction of feed of glass through the slot` adapted to pull the glassaway from the slot I5 at or approximately at the rate of feed throughthe Slot and means for severing the glass beyond the line or point atwhich tension is applied, substantially as set forth.

h IrtestimonywhereofIhaVehereuntosetmy 2O HALBERT K. HITCHCOCK.

Witnesses:

DARWIN S. WoLooTT, y F. E. GAITHER.

